U.S. Pat. No. 4,674,834 issued June 3, 1987, discloses a page scanner employing a non-coherent fiber optic bundle in which fibers extend from a linear entrance field to a rectangular exit field. The bundle is called "noncoherent" because there is no established or predetermined relationship between the ends of the fibers in the exit field and the corresponding ends of the fibers in the entrance field. The rectangular exit field is coupled to a corresponding photo-sensor array having a significantly larger number of sensors compared to the number of fibers.
The determination of a sequence of sensors of the sensor array to correspond to the sequence of fiber ends (viz: pixels) in the entrance field is carried out electronically. This determination is made during an initialization procedure where the exit field is imaged onto an array of discrete sensors and a light slit is moved along the entrance field in a manner to establish an address string for a subset of the sensors of the array which corresponds to the sequence of pixels in the entrance field. Thus, the address string organizes the electronic signals exiting the sensor array to match the organization of pixels in the entrance field.
That patent also discloses a printer using a noncoherent fiber optic bundle. The printer employs a small (cigarette-size) cathode ray tube (CRT) operative to send an electron beam to a sequence of positions on the CRT face plate. In each instance, the resulting photons from the phosphor on the CRT face plate are focused by a lens onto a corresponding fiber of the area end of a fiber optic bundle. The sequence of beam positions, dictated by the consecutive addresses of the address string, cause photons to exit the linear end of the bundle (now the exit field of the fiber optic bundle) in a coherent sequence to scan a spot of light along a line segment.
Conventiently, the area end of the bundle adjacent the CRT is coated with a suitable phosphor and formed as the CRT face plate itself. This avoids the need for a lens and more of the available light is captured. In the application of the scanned light spot to a printer, the linear end of the bundle is focused by lens or proximity on an electrostatic medium and operated to discharge that medium in accordance with the on-off light signals imposed by the CRT, thus forming a non mechanical scanner. In contrast, in a laser flying spot scanner the light from the laser is scanned by a rotating polygon. It is to be understood that in a printer, the entrance field is at the rectangular or area face of the bundle and the exit field is the linear face.